Direct Production of Ultra-High Radioisotopic Pure ${}^{64}$Cu from Natural Zinc Metal via D-D Fusion Narrowband Fast Neutron Source Irradiation

Copper-64 radiopharmaceuticals have seen limited clinical deployment primarily due to the high cost of the isotopically enriched ${}^{64}$Ni metal required for its production. In this work we demonstrate that ultra-high radioisotopic pure ${}^{64}$Cu can be directly produced in a no-carrier-added-form from natural zinc metal through irradiation with D-D fusion narrowband fast neutron sources. A highly controlled D-D fusion narrowband fast neutron source at the ELI-ALPS Laser Facility was deployed to irradiate encapsulated 99.995% pure natural zinc for 1 hour. Time-resolved gamma-ray spectroscopy of the irradiated sample over 72 hours was deployed to assess copper radioisotope activity. ${}^{64}$Cu was the only copper radioisotope detected within the irradiated sample, with a minimum and Minimum Detection Activity (MDA) threshold-corrected ${}^{64}$Cu radioisotopic purity of 99.62% and 99.97% respectively. Our result illustrates that highly controlled D-D fusion narrowband fast neutron sources have the potential to reduce the raw material production costs for ${}^{64}$Cu radiopharmaceuticals on the order of 2000 times. Cheaper ${}^{64}$Cu radiopharmaceuticals will increase their use in clinical practice, and, in-turn, increase outcomes for cancer patients receiving radionuclide therapy.